A quantitative analysis of cloud fraction, cloud radiative forcing, and cloud radiative heating rate （CRH） of the single-layered cloud （SLC） and the multi-layered cloud （MLC）, and their differences is presented,...A quantitative analysis of cloud fraction, cloud radiative forcing, and cloud radiative heating rate （CRH） of the single-layered cloud （SLC） and the multi-layered cloud （MLC）, and their differences is presented, based on the 2B-CLDCLASS-LIDAR and 2B-FLXHR-LIDAR products on the global scale. The CRH at a given atmospheric level is defined as the cloudy minus clear-sky radiative heating rate. The statistical results show that the globally averaged cloud fraction of the MLC （24.9%）, which is primarily prevalent in equatorial regions, is smaller than that of the SLC （46.6%）. The globally averaged net radiative forcings （NET CRFs） induced by the SLC （MLC） at the top and bottom of the atmosphere （TOA and BOA） and in the atmosphere （ATM） are -60.8 （40.9）, 67.5 （49.6）, and 6.6 （8.7） W m-2, respectively, where the MLC contributes approximately 40.2%, 42.4%, and 57% to the NET CRF at the TOA, BOA, and in the ATM, respectively. The MLC exhibits distinct differences to the SLC in terms of CRH. The shortwave CRH of the SLC （MLC） reaches a heating peak at 9.75 （7.5） km, with a value of 0.35 （0.60） K day-1, and the differences between SLC and MLC transform from positive to negative with increasing altitude. However, the longwave CRH of the SLC （MLC） reaches a cooling peak at 2 （8） km, with a value of -0.45 （-0.42） K day-1, and the differences transform from negative to positive with increasing altitude. In general, the NET CRH differences between SLC and MLC are negative below 7.5 km. These results provide an observational basis for the assessment and improvement of the cloud parameterization schemes in global models.展开更多
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2012CB955301)Key Program of the National Natural Science Foundation of China(41430425 and 41205015)China 111 Project(B13045)
文摘A quantitative analysis of cloud fraction, cloud radiative forcing, and cloud radiative heating rate （CRH） of the single-layered cloud （SLC） and the multi-layered cloud （MLC）, and their differences is presented, based on the 2B-CLDCLASS-LIDAR and 2B-FLXHR-LIDAR products on the global scale. The CRH at a given atmospheric level is defined as the cloudy minus clear-sky radiative heating rate. The statistical results show that the globally averaged cloud fraction of the MLC （24.9%）, which is primarily prevalent in equatorial regions, is smaller than that of the SLC （46.6%）. The globally averaged net radiative forcings （NET CRFs） induced by the SLC （MLC） at the top and bottom of the atmosphere （TOA and BOA） and in the atmosphere （ATM） are -60.8 （40.9）, 67.5 （49.6）, and 6.6 （8.7） W m-2, respectively, where the MLC contributes approximately 40.2%, 42.4%, and 57% to the NET CRF at the TOA, BOA, and in the ATM, respectively. The MLC exhibits distinct differences to the SLC in terms of CRH. The shortwave CRH of the SLC （MLC） reaches a heating peak at 9.75 （7.5） km, with a value of 0.35 （0.60） K day-1, and the differences between SLC and MLC transform from positive to negative with increasing altitude. However, the longwave CRH of the SLC （MLC） reaches a cooling peak at 2 （8） km, with a value of -0.45 （-0.42） K day-1, and the differences transform from negative to positive with increasing altitude. In general, the NET CRH differences between SLC and MLC are negative below 7.5 km. These results provide an observational basis for the assessment and improvement of the cloud parameterization schemes in global models.
